(1)Background: The prognosis of orthodontic treatment for a patient with impacted canine teeth can be affected by many factors and understanding some of the characteristics of impacted teeth can increase the effectiveness and reduce the duration of treatment. This study aims to explore the effects of positions and dentoalveolar morphological characteristics of impacted maxillary canines on the prognosis of orthodontic treatment. (2)Methods: In this study, a total of 46 adolescent individuals were divided into 3 groups: CC(no impaction), BC(unilateral maxillary buccal canine impaction), and PC(unilateral maxillary palatal canine impaction). The impacted canine and adjacent teeth were evaluated in terms of position, angulation, inclination, MD and BL widths, root length, dilaceration angle, root resorption. (3)Results: The mean values of U3Ang and U3/U2 angles were statistically significantly higher in the BC and PC groups(p<0.001). The mean values of U2RL(U3root length) and U3RD (U3root dilaceration) angle were statistically significantly lower in the BC and PC groups. (4)Conclusions: The results of this study suggest that shorter lengths and reduced volumes of the maxillary lateral incisors may lead to the ectopic eruption of canines. The higher canine angulations in the PC group make treatment more difficult and increase the degree of root resorption.